18th Division
- 18th (Eastern) Division
- 18th Armoured Division (Syria)
- 18th Artillery Division (Wehrmacht)
- 18th Cavalry Division (Soviet Union)
- 18th Division (German Empire)
- 18th Division (Imperial Japanese Army)
- 18th Division (North Korea)
- 18th Division (South Vietnam)
- 18th Guards Motor Rifle Division
- 18th Indian Division
- 18th Infantry Division (France)
- 18th Infantry Division (Greece)
- 18th Infantry Division (Poland)
- 18th Infantry Division (United Kingdom)
- 18th Infantry Division (Wehrmacht)
- 18th Infantry Division Messina
- 18th Machine Gun Artillery Division
- 18th Panzer Division (Wehrmacht)
- 18th Reserve Division (German Empire)
- 18th Rifle Division (Soviet Union)
- 18th Strategic Aerospace Division
- 39th Infantry Division (United States)
- 42nd Army (Soviet Union)
- 7th Mechanized Corps (Soviet Union)